title: Does "spreading" skin dose by rotating the C-arm during an intervention work?
abstract: OBJECTIVE
  To determine if C-arm rotation is beneficial for reducing peak skin dose (PSD) in interventional radiology (IR) and, if so, under what circumstances.
  
  
  METHODS
  The Monte Carlo method was used to perform ray tracing for detailed analyses of the effect of C-arm rotation on PSD across a range of patient sizes, C-arm configurations, and procedure types. Automatic dose-rate control curves on modern fluoroscopic systems were measured for input into the simulations.
  
  
  RESULTS
  Rotating the C-arm to reduce the PSD is in most cases contraindicated and results in increased PSD when the C-arm is rotated from an original posteroanterior projection, in some cases resulting in a PSD increase by a factor of 5 or more. When prophylactic rotation was performed before a procedure, however, and the C-arm was rotated between opposed, distinct oblique angles, substantial reduction in PSD was achieved for patients of any size.
  
  
  CONCLUSIONS
  Rotating the C-arm during a procedure with the aim of "spreading" dose on the skin of the patient may not result in a reduction in PSD and may increase PSD. However, when used as a prophylactic measure combined with tight x-ray beam collimation, C-arm rotation can be used as a tool to reduce PSD. Tight collimation greatly increases the benefit of C-arm rotation.
authors.affiliation: Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Pasciak
authors.forename: A Kyle
authors.initials: AK
authors.lastname: Jones
mesh_terms: D001822:Body Burden; D049628:Body Size; D003198:Computer Simulation; D004867:Equipment Design; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D009010:Monte Carlo Method; D011829:Radiation Dosage; D011855:Radiodermatitis / Q000209:etiology / Q000517:prevention & control*; D015641:Radiography, Interventional / Q000009:adverse effects / Q000295:instrumentation*; D012399:Rotation; D012867:Skin / Q000528:radiation effects*